A heat wave is blistering much of the country, from Texas to New York.

Excessive heat warnings or advisories were issued in 18 states Thursday, from the South through the Midwest and into the Great Plains.

Temperatures reached into the mid-to upper-90s. Intense humidity sent the heat index soaring over 100.

"I've been in meteorology and weather for over 44 years, and I've never seen the heat index as high as what we've had today," said Bobby Boyd, a meteorologist with the National Weather Service in Nashville. "It's just suffocating out there."

In one heat-related death, one man in Tennessee died while cutting his lawn. In Louisiana and Arkansas, the heat actually buckled highways and has led to more than a dozen wildfires.